Fuel injection pump



Aprll 18, 1961 A. DREISIN ETAL 2,980,092

FUEL INJECTION PUMP Filed July 1, 1957 r 3 Sheets-Sheet 1 J l 4 IINVENTOR April 1961 A. DREISIN ETAL 2,980,092

FUEL INJECTION PUMP 3 Sheets Sheet 2 .2. w A J V r. r r

K 3 v? j C Flled July 1 1957 FIVE/sf April 18, 1961 A. DREISIN ETAL2,930,092

FUEL INJECTION PUMP Filed July 1, 1957 3 Sheets-Sheet 3 2,980,092Patented Apr. 18, 1961 FUEL INJECTION PUMP Alexander Dreisin, HighlandPark, and Louis G. Kaplan, Evanston, Ill., assignors, by mesneassignments, to Allis-Chalmers Manufacturing Company, a corporation ofDelaware Filed July 1, 1957, Ser. No. 668,971

11 Claims. (Cl. 123-439 This invention relates to an improved injectionpump of the distributor type for internal combustion engines which usesfuel injection to introduce the fuel into the engine cylinders eitherdirectly into the combustion chamber or into the inlet manifold ofdiesel and gasoline engines.

An object of the invention is to provide a simple and effective meansfor both pumping and distributing fuel Within a fuel injection systemfor multiple cylinder applications to internal combustion engines.

Another object of the invention is to provide a single plunger fuel pumpfor internal combustion engines in which the plunger also functions as adistributor'of fuel to the several combustion chambers or intakemanifold of a multicylinder engine of either twoor fou -cycle type.

Another object of the invention is the provision of a plunger-operatedfuel injection pump in which a delivery valve is located within theplunger and moves to closed position to effect a rapid reduction indelivery'pressure.

Another object of the invention is the provision of a plunger-operatedfuel injection pump having a pump chamber into which the plunger isinserted to effect a fuel delivery, in which communication between thepump chamber and the fuel supply is maintained throughout the entireretractive movement of the plunger to insure full charging of the pumpchamber and to avoid formation of a vacuum therein.

Another object of the invention is the provision of a single plungerfuel pump in which the plunger is moved rectilinearly to effect a fueldelivery and is rotated to deliver the fuel to the proper combustionchamber of a multiple-cylinder internal combustion engine.

Another object of the invention is the provisionof. a fuel injectionpump in accordancewith the preceding object in which means are providedfor controlling either, or both, of the points of initiationancltermination of fuel delivery.

Other objects and features of the invention ,will be readily apparent tothose skilled in the art from the following specification andaccompanying drawings in which} Fig. 1 is a partial vertical sectionalview of the fuel injection pump of this invention;

Fig. 2 is an enlarged detail sectional view of the structure of Fig. 1showing the delivery valve and the fuel supply control; V

Fig. 3 is a detail sectionalrview of the structure illustrated in Fig. 1taken on the line 33 thereof;

shown), a shaft 2 carrying a earn 3 and a miter gear 4.

' The surface of the cam 3 is provided with a plurality of lobes. Thenumber of lobes on the cam 3 is dependent on the speed of rotation'ofthe shaft 2 and the number of strokes of a piston in one cycle ofoperation of an internal combustion engine that is equipped with thispump. That is, in a four-cycle internal combustion engine with the shaft2 rotating at one-half crank shaft speed, the number of lobes on the cam3 would correspond to the number'of cylinders in the engine.

Within an opening incasing 1 above the cam 3 is disposed a cage 6 havingan interconnected outer wall 7.

and an inner wall 8, defining an annular recess 9 in which is rotatablydisposed a miter gear 11, meshing with miter gear 4 on the shaft 2. ,Anyforce transmitted upwardly from gear 4 to the gear 11 isapplied by anannular bearing 12 to a snap ring 13. The cage 6 is loosely retained inassembled relation with casing 1 by a screw 14 and a washer 15.

The-inner surface of the inner wall 8 of cage 6 forms a central bore inwhich is disposed a reciprocahle tappet 16. The lower face of the tappet16 is provided with a socket 17 in which is disposed a roller 18 engagedby the surface of the cam 3 and cooperating with the lobes 5 to effectreciprocation of the tappet 16.

Rigidly mounted on the lower casing 1 and clamping the cage 6therebetween is an upper casing 19. Casing 19 is provided witha centralbore in which is disposed the operating plunger 21. The upper end of thebore in casing 19 is closed by a plug 22 and between the lower end ofplug 22 and the upper end of plunger 21 is the pump chamber 23. Adriving. disk 24 is keyed on the plunger 21 by a flat 25 (Fig. 4) forcommon rotative movement while permitting the plunger 21 to movelongitudinally relative to the disk 24. Two pairs of' projections 26extend downwardly from the under surface of the disk 24 and between eachpair is disposed a tongue 27 extending from the miter gear 11. Upon Fig.4 is a detail sectional view of the structure illus- 1, having journaledtherein by suitable bearings' (not the lower end of the plunger 21 ismounteda spring seat 28 and between this seat and the under surface ofdriving disk 24 is disposed a spring 29 which biases the plunger 21toward retracted position and the end of plunger 21 tion forming asealing surface 33 and the intermediate portion forming an enlargedvalve discharge passage. 34. Valve means 35 is disposed within thecentral bore of plunger 21 and these parts are shown in greater detailin the enlarged view of Fig. 2. The valve 35 has a stem 36 and a head37and has a central passage 38 there through, connecting the inlet passage32 with the pump chamber 23. A spring 39 is disposed. between the undersurface of the head 37 ofvalve 35 and aishoulder within the central boreof plunger 21 and biases the valve into closed position, the valveclosure being cifected by engagement of the sealing ring 41'with surface33. A sealing ring 42 prevents communication between the inlet anddischarge passages about the stem 36. A snap ring 43 limits the closedposition of-the valve, 35.

Extending from chamber 34 to the periphery of plunger 21 is a dischargeslot or opening 44 whichis successively indexed with discharge passages45, spaced circumferentially about the plunger 21 and corresponding innumber to the number of engine cylinders. The, discharge passages 45 areshown in Fig. 1 as terminating in exterior sockets 46 which are providedfor the corn; nection ofhigh-pressure tubing, which may in turn beconnected to injection nozzles.

Within' the casing 19 and communicating with itsgcen-j I on thedeveloped view of Fig. 5.

tral bore is a fuel chamber 47 which is supplied with fuel by aconventional fuel supply pump. About the plunger 21 at its inlet passage31 and extending into chamber 47 is a sleeve 48, shown in detail inFigs. 2 and 3. The sleeve 48 is comprised of an annular central portion49 having in its upper surface an annular recess 51 communicatin throughan inlet passage 52 with chamber 4-7. Axially extending passages 53 areprovided in the form of slots in the central bore of annular portion 49,communicate with the annular recess 51, and are spaced circumferentiallyabout the bore. The passages 53 are equal in number to the number ofengine cylinders and have therebetween inlet sealing portions 54. Uponthe opposite faces of the annular portion 49 are mounted disks 55 and 55to close the passages thereat. Plunger 21 is freely movable relative tothe sleeve 48 both rotatably and rectilinearly. in the sleeve 48 theannular portion 49 and the disks 55 and e are rigidly joined togetherinto a unitary structure.

The lower sleeve disk 56 is provided with an extension 57 having a slot53 in which is disposed a crank 59 which not only normally holds thesleeve 48 in place against undesired rotation but also provides a meanseffecting limited rotation of the sleeve to control the point ofinitiation of fuel injection. The crank 59 is mounted upon a shaft 61 soas to be rotatable therewith. Shaft 61 is journaled in a hub til-whichis supported on an exterior plate 63 mounted on the casing 19. Keyed 'onthe exterior end of the shaft 61 are an operating arm 64 and a stop arm65 which is engaged with stops on on the plate 63 to limit rotativemovement of the shaft 61 and hence to limit rotation of the sleeve 48relative to the casing 19. An oil seal ring 67 is provided between theshaft 61 and the hub 62.

Fig.- 5 is a developed view of the internal bore of the control sleeve48, showing the relation of the inlet passage 31 relative thereto invarious positions, represented by the circles A, B and C. The arrow Drepresents the direction of relative inlet passage motion. The verticalmovement of the undulating path of the circles represents the length ofthe plunger stroke.

In the operation of the pump, the shaft 2 is connected to be rotated bythe engine which it supplies, for example,

by direct connection to the engine cam shaft so as to rotatesynchronously with the engine in the case of a two-cycle engine andthrough a reduction gear to rotate at one half synchronous engine speedin the case of a four-cycle engine. As the shaft 2 rotates, the nodes 5on the surface of cam 3 are successively engaged with the roller 13toetlect upward movement of the plunger 21 into the pump chamber 23 toexpel fuel therefrom. The plunger 21, tappet t6, and roller 18, at alltimes follow the surface of the cam 3, being biased downwardly by thespring 29. Also as the shaft 2 rotates, the miter gear 4 rotates thegear 11 and it in turn, through the engagement of the tongues 27 withthe projections 26, rotates the driving disk 24 to effect rotation ofthe plunger 21 to which his keyed by the flat 25'. Rotation of theplunger 21 indexes the dischargeslot 44 successively with the dischargeopenings 45 leading to the engine cylinders and also indexes theentrance passage 31, either with the passages 53, the sealing portions54-, or the annular recess 51.

As shown in Fig. 1, the operating plunger 2i of the pump is in retractedposition corresponding to point C In this position communication isestablished between supply chamber 47 and pump chamber 23, throughsleeve inlet passage 52, annular recess 51, sleeve axial passage 53,plunger inlet passage 31, vertical plunger passage 32, and the bore orpassage 3% through the valve 35. As the shaft 2 rotates, the operatingplunger 21 will be simultaneously moved upwardly by the lobes on com 3and rotated by the miter gear 4. So long as the entrance passage 31remains in communication with a sleeve axial passage 53, no pressure isbuilt up within the pump chamber 23 as the fuel therein returns freelyto the supply chamber 47. When the inlet passage 31 is completely sealedby a portion 54 in the position A of Fig. 5, pump chamber 23 is nolonger in communication with supply chamber 47 and further upwardmovement of the plunger 21 causes a buildup of pressure within chamber23 and effects downward movement of discharge valve 35 against the biasof spring 39 until sealing ring 41 clears the upper shoulder of thechamber 34- at which time the fuel in chamber 23 passes directly intodischarge chamber 34 and through discharge slot 44, passage 45 to theindexed engine cylinder.

This fuel delivery continues from inlet passage 31 position A in Fig. 5to inlet passage position B where it has just reached the horizontaledge of the annular recess 51. As soon as the edge of the inlet passagepasses the edge of the annular recess, the pump chamber 23 is againplaced in free communication with the supply chamber 4 7. The pressureWithin chamber 23 is relieved and the valve 35 snap-s to its closedposition, in which it is shown in Fig. 2. Continued upward movement ofthe plunger 21 from the inlet passage position B to the end of theplunger stroke only expels fuel from the chamber 23 back into the supplychamber 47.

As shaft 2 continues to rotate, plunger 21 is retracted under the biasof spring 29 as the roller 18 follows the opposite slope of the camlobe, the plunger also rotating to follow the downward path indicated bythe letter D in Fig. 5. As will be seen from Fig. 5, the inlet passage31 is in communication with a passage 53 throughout the entire downwardstroke of the plunger 21, thus making it possible to charge the pumpchamber 23 with fresh fuel throughout the entire downward stroke of theplunger. This affords a maximum percentage of time for charging the pumpchamber and avoids formation of a vacuum therein, importantconsiderations for high-speed operations and in the use of volatilefuel.

As the valve 35 moves into the closed position of Fig. 2 at thetermination of fuel injection, the volume of the discharge cavitiesbeyond the valve 35 is increased by the product of the difference inarea between the bore in which the head 37 is located and the bore inwhich the lower end of stem 36 is located multiplied by the stroke ofthe valve. This increase in volume causes a rapid re duction inhydraulic pressure in the passages beyond the delivery valve 35,including passage 45, connected tubing, and the injection nozzle. Thisrapid reduction in pressure is important in avoiding efflux of the fuelfrom the nozzle which might otherwise occur during a gradual reductionof pressure in the pump.

In the pump heretofore described, termination of fuel injection willalways occur at the same point in the upward stroke of the plunger 21when the entrance passage 31 overrides the horizontal edge of theannular recess 51 as occurs just beyond the position B of Fig. 5. Thepoint of the upward stroke ,of the plunger '21 at which fuel injectionis initiated can, however, be varied by rotation of arm 64 to eifectrotation of the sleeve 48 relative to the casing 19. If the sleeve 48 isrotated in the same direction in which plunger 21 is rotated, this willcorrespond to a movement to the right of the developed sleeve shown inFig. 5. This means that the inlet'passage 31 will not be closed untillater in the upward stroke of plunger and thus fuel injection also willbe initiated later. ince the point in the stroke at which fuel injectionisterminated remains the same, as the inlet opening 31 overrides thehorizontal edge of the recess 51, theresult of this sleeve rotation isto lessen the time of injection and hence the quantity of fueldelivered. Similarly, movement of the sleeve 48 in the directionopposite to the direction of plunger rotation would effect closing ofthe inlet passage 31 earlier in the upward stroke of the plunger andcause a corresponding increase in the time and quantity of fuelinjection. The arm 64 can thus beiconnected to any means either manualor automatic to change the quantity of fuel delivery in proportion tothe demands of the engine.

In Fig. 6 a modified form of injection pump is shown. While the figureillustration differs from the preferred form of Fig. 1 in other andminor details, only the salient differences relating to the dischargevalve and to the vertical adjustment of the control sleeve will bedescribed. In this modification the delivery valve is no longer locatedwithin the operating plunger but is now mounted in the bore within theexterior casing which is here numbered 81, the operating plunger beingshown at 82, with an inlet passage 83 and a central bore 84 leading tothe pump chamber 85. Stationarily mounted within the casing 81, aboveand in communication with the pump chamber 85, is a valve seat 86 heldin place through the plug 87 which internally carries a spring 88pressing against valve means, herein illustrated as a ball 89. Angularand horizontal passages 91 and 92 connect the discharge side of thevalve to the central bore within the casing 81. The plunger 82 isprovided with an' annular recess 93 communicating with a discharge slot94 adapted tobe indexed with successive discharge passages 95. In thismodification fuel trapped in pump chamber 85 when the inlet passage 83is sealed lifts the ball 89 from valve seat 86 to permit delivery offuel to the annular space 80 through slots in a ring 90 and on throughthe passages 91 and 92 to the annular recess 93, whence it dischargesthrough discharge slot 94 into discharge passages 95. I

Fig. 6 also illustrates control of the point of termination of fuelinjection in addition to control of the point of initiation of fuelinjection. Here the control sleeve is indicated at 96 and has a slot 97in a portion of its periphery in which is received a pin 98eccentrically mounted at the end of a shaft 99. Since the sleeve 96 isfreely movable relative to the plunger 82, it is seen that rotation ofthe shaft 99 will be accompanied by a movement of the pin 98 having avertical component so that the sleeve 96 will be moved verticallyrelative to the casing 81. Referring to Fig. this corresponds to avertical movement of the developed sleeve. If the sleeve 96 is movedupwardly the inlet passage 83 will not reach the edge of the annularrecess until later in the upward stroke of the plunger. Assuming that inthis operation the sleeve 96 is not rotated, the upward movement willresult in a longer period of fuel injection and delivery of a greaterquantity. By suitable adjustment of the rotative and vertical positionsof the controlling sleeve 96 both the beginning and end of fuelinjection may be advanced or retarded as desired to adjust the quantityof fuel delivered to the engine and the timing relation between pumpoperation and engine piston displacement. In the form in which the pumphas been described and illustrated it is an independent subassemblyafiording complete freedom of location and choice of other parts of thefuel supply system. The pump of this invention lends itself equally wellto a construction where the system constitutes a selfcontained unit withits owndrive, supply pump and governor.

What is claimed is: 1. An injection pump comprising a casing having abore therein, a plunger in said bore freely movable longitudinally androtatably of the casing, a pump chamber in said bore at the interior endof said plunger into which the plunger is moved in its working stroke,means on said pump for reciprocating and rotating said plunger to effectdelivery of fluid from said chamber, said plunger having an inletpassage. communicating with said pump chamber and having an inletopening at the periphery. of.

the plunger, a sleeve surrounding said plunger and in which the plungeris freely movable both longitudinally and rotatably, said sleeve havingan inlet opening-and a plurality of passages therein communicating withsaid sleeve inlet opening and disposedadjacent to said plunger inletopening so as to becyclically' connected and disconnected therewithduring rotational 'and longitudinal movements of the plunger, saidplunger having a discharge passage communicating with a dischargeopening at the periphery thereof, valve means carried by said pumpconnecting said pump chamber with said discharge opening upon buildup ofpressure within the chamber during the working stroke of the plunger,said casing having discharge passages leading from said bore to thecasing exterior, said casing passages being spaced circumferentiallyabout said plunger and successively indexed with said plunger dischargeopening as the plunger rotates, and means on said casing for adjustingsaid sleeve angularly and axially of said plunger to effect theconnection and disconnection of the inlet opening independently of eachother.

2. An injection pump comprising a casing having a bore therein, aplunger in said bore freely movable longitudinally and rotatably of thecasing, a pump chamber in said bore at the interior end of the plungerinto which the plunger is moved in its Working stroke, means on saidpump for reciprocating and rotating said plunger to effect delivery offluid from said chamber, a sleeve about said plunger having a boretherethrough within which the plunger is freely rotatably andlongitudinally movable, an annular recess in the bore of said sleeve, aninlet opening extending from said anhularv recess to the exterior of thesleeve, a plurality of circumferentially spaced, axially extending slotsin the bore of said sleeve communicating with said annular recess, aninlet passage within said plunger communicating with said pump chamberand extending to an inlet opening in the periphery of the plungerdisposed I at said sleeve so as to be in communieation with said axialslots and annular recess during portions of the plunger stroke andsealed by the sleeve during another portion of the stroke in which fueldelivery is effected, a discharge passage in said plunger communicatingwith a discharge opening at the periphery thereof, valve means on saidpump connecting said pump chamber Withsaid discharge opening uponbuildup. of pressure Within the chamber during the working stroke of.the plunger, and discharge passages in said casing leading from saidhereto the casing exterior, said I casing passages being spacedcircumferentially about said plunger and successively indexed withsaidplunger discharge opening as the plunger rotates.

3. An injection pump comprising a casing having a bore therein, aplunger in said bore freely movable longitudinally and rotatably of thecasing, a pump chamber in said bore at the interior end of the plungerinto within said plunger communicating with saidpump 'chamher andextending to an inlet'opening in the periphery of the plunger disposedat said sleeve so as to be in .communication with said axial slots andannular recess during portions of .the plunger stroke and sealed by thesleeve during another portion of the stroke in which fuel delivery iseffected, closing of the plunger inlet opening by the wall of the sleevebetween the axial slots trapping fluid within the pump chamber andinitiating fluid delivery, and communication of the plunger inletopening with the annular recess relieving pump charnber pressure toterminate fluid delivery.

4. Aninjection pump comprising a casing having a bore therein, a plungerin said bore freely movable longitudinally and rotatably of the casing,a pump chamber in said bore at the interior endof the plunger into whichthe plunger is moved in its working stroke, means on said;

pump for reciprocating and rotating said plunger to effect delivery offluid from said chamber, a sleeve about said plunger having a boretherethrough within which the plunger is freely rotatably andlongitudinally movable, an annular recess in the bore of said sleeve, aninlet opening extending from said annular recess to the exterior of thesleeve, a plurality of circumferentially spaced, axially extending slotsin the bore of said sleeve communicating with said annular recess, aninlet passage Within said plunger communicating with said pump chamberand extending to an inlet opening in the periphery of the plungerdisposed at said sleeve so as to be in communication with said axialslots and annular recess during portions of the plunger stroke andsealed by the sleeve during another poition of the stroke in which fueldelivery is effected, closing of the plunger inlet opening by the Wallof the sleeve between the axial slots trapping fluid within the pumpchamber and initiating fluid delivery, communication of the plungerinlet opening with the a nular recess relieving pump'chamber pressure toterminate fluid'delivery, and means on said pump for rotating saidsleeve relative to the casing to vary the point in the cycle at whichthe wall of the sleeve bore seals oil the plunger inlet opening andhence the point at which fluid delivery begins.

5. An injection pump comprising a casing having a bore therein, aplunger in said bore freely movable longitudinally and rotatably of thecasing, a pump chamber in said bore at the interior end of the plungerinto which the plunger is moved in its working stroke, means on saidpump for reciprocating and rotating said plunger to effect delivery offluid from said chamber, a sleeve about said plunger having a boretherethrough within which the plunger is freely rotatably andlongitudinally movable, an annular recess in the bore of said sleeve, aninlet open ing extending from said annular recess to the exterior of thesleeve, a plurality of circumferentially spaced, axially extending slotsin the bore of said sleeve communicating with said annular recess, aninlet passage Within said plunger communicating with said pump chamberand extending to an inlet opening in the periphery of the plungerdisposed at said sleeve so as to be in communication with said axialslots andannular recess during portions of the plunger stroke and sealedby the sleeve during another portion of the stroke in which fueldelivery is effected, closing of the plunger inlet opening by the Wallof the sleeve between the axial slots trapping fluid within the pumpchamber and initiating fluid delivery, communication of the plungerinlet opening with the annular recess relieving pump chamber pressure toterminate fluid delivery, and means on said pump for moving said sleevelongitudinally of said plunger so as to vary the point in the plungerstroke at which the plunger inlet opening communicates with the annularrecess and hence vary the point in the cycle at "which fuel delivery isterminated.

6. An injection pump comprising a casing having a bore therein, aplunger in said bore freely movable longitudinally and rotatably of thecasing, a pump chamber in said core at the interior end of the plungerinto which the plunger is moved in its working stroke, means on saidpumpfor reciprocating and rotating said plunger to effect delivery offluid from said chamber, a sleeve about said plunger having a boretherethrough Within which the plunger is freely rotatably andlongitudinally movable,

an annular recess in the bore of said sleeve, an inlet opening extendingfrom said annular recess to the exterior of the sleeve, aplurality ofcircumferentially spaced, axially extending slots in the bore of saidsleeve communicating with said annular recess, an inlet passage Withinsaid plunger communicating with said pump chamber and extending to aninlet opening in the periphery of the plunger disposed at said sleeve soas to be in communication with said axial slots and annular recessduring portions ofthe plunger stroke and sealed by the sleeve duringanother portion of the stroke in which fuel delivery is effected,

closing of the plunger inlet opening by the Wall of the sleeve betweenthe axial slots trapping fluid within the pump chamber and initiatingfluid delivery, communication of the plunger inlet opening with theannular recess relieving pump chamber pressure to terminate fluiddelivery, means on said pump for rotating said sleeve relative to thecasing to vary the point in the plunger stroke at which the wall of thesleeve bore seals the plunger inlet opening, and means for moving saidsleeve longitudinally of said plunger to vary the point in the plungerstroke at which the plunger inlet opening communicates with tie annularrecess.

7. An injection pump comprising a casing having a bore therein, aplunger in said bore freely movable longitudinally and rotatably of thecasing, a pump chamber in said bore at the interior end of the plungerinto which the plunger is moved in its working stroke, means forreciprocating and rotating said plunger to eflect delivery of fluid fromsaid chamber, a source of fluid, means operable on rotation andlongitudinal movement of said plunger to cyclically connect anddisconnect said chamber with said fluid supply source, saidlast-mentioned means including a bore in the interior end of saidplunger having inlet and outlet openings communicating with theperiphery of the plunger and control means sealing and opening saidplunger inlet opening, a valve within said plunger bore and having ahead providing the valve seal in a bore portion of one diameter adjacentthe end of the plunger, said valve having a stem extending lengthwise ofthe bore and scaling in a bore portion of smaller diameter, an openingthrough said stem freely communicating the inlet portion of the plungerbore With the pump chamber, a discharge chamber about said valve stemcommunicating with said pump chamber when said valve is open, and theplunger discharge opening communicating with said discharge chamber, anddischarge passages in said casing leading from the casing bore to theexterior and successively indexed with said plunger discharge opening asthe plunger rotates.

8. An injection pump comprising a casing having a bore therein, aplunger in said bore freely movable longitudinally and rotatably of thecasing, a pump chamber in said bore at the interior end of the plungerinto which the plunger is moved in its working stroke, means forreciprocating and rotating said plunger to effect delivery of fluid fromsaid chamber, a source of fluid, means operable on rotation andlongitudinal movement of said plunger to cyclically connect anddisconnect said chamber with said fluid source, said last-mentionedmeans including a bore in the interior end of said plunger having inletand outlet openings communicating with the periphery of the plunger andcontrol means sealing and opening said plunger inlet opening withrespect to the fluid source, a valve within said .plunger bore andhaving a head providing the the valve seal in a bore portion of onediameter adjacent the end of the plunger, said valve having a stemextending lengthwise of the bore and sealing in a bore portion ofsmaller diameter, an opening through said stem ifreely communicating theinlet portion of the plunger bore with the pump chamber, a dischargechamber about said valve stem communicating with the pump chamber whenthe valve is open, the head of the valve as it opens moving into thedischarge chamber to reduce the volume thereof during fluid deliverywhereby return of the valve to sealing position will be accompanied by arapid increase in volume and reduction of pressure within the dischargechamber, said discharge opening communicating with said dischargechamber, and discharge passages in said casing leading from said casingbore to the exterior and successively indexed with said plungerdischarge opening as the plunger rotates.

9. An injection pump comprising a casing having a bore therein, aplunger in said bore freely movable longitudinally and rotatably of thecasing, a pump chamber in said bore at the interior end of the plungerinto which the with the plunger inlet passage alternately placed incom-- munication with and sealed from the sleeve bore passages uponrotational and longitudinal movements of the plunger, a valve carried bysaid plunger within its bore and comprising a headed portion sealingwithin a section of the bore of one diameter adjacent the end of theplunger and a stem extending from the head and scaling in a plunger boresection of lesser diameter, a fluid supply passage extending throughthe, stem and head of said valve to place the pump chamber incommunication with the plunger inlet passage, means biasing said valveinto sealing position, a discharge chamber about the stem of said valve,a discharge passage leading from said discharge chamber to the peripheryof the plunger, and discharge passages in said casing leading from saidcasing bore to the exterior and successively indexed with said plungerdischarge passage as the plunger rotates.

10. An injection pump comprising a casing having a bore therein, aplunger in said bore freely movable longitudinally and rotatably of thecasing, a pump chamber in said bore at the interior end of the plungerinto which the plunger is moved in its working stroke, means forreciprocating and rotating said plunger to effect delivery of fluid fromsaid chamber, a source of fluid, a sleeve mounted on said plunger forfree longitudinal and rotative movement of said plunger relativethereto, a'plurality of intercommunicating passages in the bore of saidsleeve, an inlet passage connecting said bore passages with said fluidsource, a bore in the interior end of the plunger having an inletpassage leading to the periphery thereof,

with the plunger inlet passage alternately placed in communication withand sealed from the sleeve bore passages upon rotational andlongitudinal movements of the plunger, a valve carried by said plungerwithin its bore and comprising a headed portion sealing within a sectionof the bore of one diameter adjacent to the end of the plunger and astem extending from the head and sealing in a plunger bore section oflesser diameter, a fluid supply tion in pressure within thedischargetchamber, and a plurality of discharge passages in said casingextending from the casing bore to the exterior and successively-indexedwith said plunger discharge passage as the plunger rotates.

11. A fuel injection pump for internal combustion engines comprising ashaft, a cam on said shaft having a plurality of lobes thereon, a gearon said shaft, a pump operating plunger, means intermediate said plungerand cam for effecting reciprocation of said plunger in response. torotation of said shaft, a gear connected to said plunger and meshingwith said first gear to effect rotation of said plunger in response torotation of said shaft, a pump chamber into which the plunger is movedin its working stroke, a sleeve about said plunger having a bore inwhich the plunger is freely movable both rotatably and longitudinally,said plunger having a passage through the interior I volume of thedischarge chamber during the delivery period whereby return of the valveinto sealing position is accompanied by a rapid increase in volume andreducend thereofcommunicating with the pump chamber and with an inletopening in the periphery of the plunger disposed within said sleeve, aplurality of circumferentially spaced, axially extending recesses in thebore of said sleeve equal in number to the number of engine cylinders,an annular recess in said sleeve bore interconnecting said axiallyextending recesses, an inlet passage in said sleeve interconnecting saidannular recess and said fuel source, a plunger inlet opening beingcyclically connected with said sleeve recesses and sealed therefrom asthe plunger is rotated and longitudinally moved in response to rotationof said shaft, and means for rotating and longitudinally shifting saidsleeve.

12. A fuel injection pump for internal combustion engines comprising ashaft, a cam on said shaft having a plurality of lobes thereon, a gearon said shaft, a pump operating plunger, means intermediate said plungerand cam for effecting reciprocation of said plunger in response torotation of said shaft, a gear connected to said plunger and meshingwith said first gear to elfect rotation of said plunger inresponse torotation of said shaft, a pump chamber into which the plunger is movedin its working stroke, a sleeve about said plunger having a bore inwhich the plunger is freely movable both rotatably and longitudinally, apassage through the interior end of said plunger communicating with thepump chamber and with an inlet opening in the periphery of the plungerdisposed within said sleeve, a plurality of circumferentially spaced,axially extending recesses in the bore of said sleeve equal in number tothe number of engine cylinders, an annular recess in said sleeve boreinterconnecting said axially extending recesses, an inlet passage insaid sleeve interconnecting said annular recess and a fuel source, saidplunger inlet opening being cyclically connected with said sleeverecesses and sealed therefrom as the plunger is rotated andlongitudinally moved in response torotation of said shaft, means on saidpump for adjusting said sleeve angularly, and means on said pump forlongitudinally shifting said sleeve.

13. A fuel injection pump for internal combustion engines comprising ashaft, a cam on said shaft having a plurality of lobes thereon, a gearon said shaft, a pump v operating plunger, means intermediate saidplunger and cam for effecting reciprocation of said plunger in responseto rotation of said shaft, a gear connected to said plunger and meshingwith said first gear to effect rotation of said plunger in response torotation of said shaft, a pump chamber into which the plunger is movedin its working stroke, a source of fuel, a sleeve about said plungerhaving a, bore in which the plunger is freely movable both rotatably andlongitudinally, a passage through the interior end of said plungercommunicating with the pump chamber and with an inlet opening in theperiphery of the plunger disposed within said sleeve, a plurality ofcircumferentially spaced, axially extending recesses in the bore of saidsleeve equal in number tothe number of engine cylinders, an annularrecess in said sleeve" bore interconnecting said axially extendingrecesses, an inlet passage in said sleeve interconnecting said annularrecess and said fuel source, said plunger inlet opening being cyclicallyconnected with said sleeve recesses and sealed therefrom as the plungeris rotated and longitudinally moved in response to rotation of saidshaft, a stationary valve seat having an opening therethroughcommunicating with said pump chamber, a spring biased ball in said valveseat and normally closing the opening therethrough, an annular recess inthe periphery of said plunger, stationary passages connecting thedischarge side of said valve seat with the annular recess in theplunger, and a longitudinally extending peripheral discharge slot insaid plunger communicating with the annular recess therein, and aplurality of stationary discharge passages circnmferentially spacedabout said plunger and indexed with said discharge slot as the plungerrotates. i

14. An injection pump comprising: a casing having a bore therein; aplunger in said bore freely movable longitudinally and rotatably of thecasing; a pump chamber in said bore at the interior end of the plungerinto which the plunger is moved in its working stroke; means on saidpump for reciprocating and rotating said plunger to eiiect delivery offluid from said chamber; a sleeve about said plunger having a boretherethrough Within which the plunger is freely rotatably andlongitudinally movable; an annular recess in the boreof said sleeve; aninlet opening in said sleeve extending from said annular recess to theexterior of said sleeve; an axially extending recess in the bore of saidsleeve communicating With said annular recess; and an inlet passagewithin said plunger communicating with said pump chamber and extendingto an inlet opening in the periphery of the plunger disposed at saidsleeve so as to be in communication with said axial and annular recessesduring portions of the plungers stroke and sealed by the bore of saidsleeve during another portion of the stroke in which fuel delivery iseffected, closing of the plunger inlet opening by the bore of saidsleeve upon said plunger inlet opening moving from registry with one ofsaid recesses trapping fluid within the pump chamber thereby initiatingfluid delivery and communication of the plunger inlet opening with theother of said recesses relieving pump chamber pressure to terminatefluid delivery.

15. The fuel injection pump set forth in claim 14 and further includingadjusting mechanism for varying the beginning and ending of injection,said adjusting mechanism comprising: means on said pump for rotatingsaid sleeve relative to the casing to vary the point in the plungersstroke at which the plunger inlet opening communicates with the axialrecess; and means on said pump for moving said sleeve longitudinally ofsaid plunger to vary the point in the plungers stroke at which theplunger inlet opening communicates with said annular recess.

16. An injection pump comprising: a casing having a bore therein, aplunger in said bore freely movable longitudinally and rotatably of thecasing, a pump chamber in said bore at the interior end of the plungerinto which the plunger is moved in its Working stroke, means forreciprocating and rotat ng said plunger to effect delivery of fluid fromsaid chamber, a source of fluid, means operable on rotation andlongitudinal movement of said plunger to cyclically connect anddisconnect said chamber with said fluid supply source, said lastmentioned means including a plunger bore in the interior end of saidplunger having inlet and outlet openings communicating with theperiphery of the plunger and control means sealing and opening saidplunger inlet opening, a

valve within said plunger bore and having a head providing the valveseal in a portion of said plunger bore of one diameter adjacent theinterior end of the plunger, said valve having a stem extendinglengthwise of the bore and scaling in a portion of said plunger bore ofsmaller diameter than said one diameter, passage means connecting theinlet opening of the plunger bore with the pump chamber in free flowingfluid communication, a discharge chamber about said valve stemcommunicating with said pump chamber when said valve is open, and theplunger outlet opening communicating with said discharge chamber, anddischarge passages in said casing leading from the casing bore to theexterior and successively indexed with said plunger outlet opening asthe plunger rotates.

17. An injection pump comprising a casing having a bore therein, aplunger in said bore freely movable lon gitudinally and rotatably of thecasing, a pump chamber in said bore at the interior end of said plungerinto which the plunger is moved in its working stroke, means on saidpump for imparting reciprocating and rotating movements to said plungerto effect delivery of fluid from said pump chamber, said plunger havinginlet passage means establishing fluid communication between, said pumpchamber and the periphery of the plunger, a sleeve having a bore inwhich said plunger is freely movable both longitudinally and rotatively,said sleeve being adjustable relative to said casing rotatively aboutand longitudinally of said plunger, a plurality of circumferentiallyspaced inlet sealing portions formed in said bore of said sleevecyclically blocking said inlet passage means during longitudinal androtating movements of said plunger, means on said pump for rotativelyadjusting said sleeve relative to said casing and plunger, and means onsaid pump for adjusting said sleeve longitudinally of said casing andplunger, one of said rotative and longitudinal adjustments of saidsleeve changing the point on said working stroke at which said sealingportions block said inlet passage means to begin injection and the otherof said rotative and longitudinal adjustments of said sleeve changingthe point on said working stroke at which said sealing portions cease toblock said inlet passage means to end injection.

References Cited in the file of this patent Aldinger Oct. 22, 1957

